Asp.net uploads large files

Using system. Web;
Public class upload
{
Public void saveupload ()
{
Httpapplication application1 = sender as httpapplication;
Httpworkerrequest request1 = (httpworkerrequest) (iserviceprovider) httpcontext. Current). getservice (typeof (httpworkerrequest ));
Try
{
If (application1.context. Request. contenttype. indexof ("multipart/form-Data") <=-1)
{
Return;
}
// Check the hasentitybody
If (! Request1.hasentitybody ())
{
Return;
}

Int num1 = 0;
Timespan span1 = datetime. Now. Subtract (this. begintime );

String text1 = application1.context. Request. contenttype. tolower ();

Byte [] buffer1 = encoding. ASCII. getbytes ("/R/n --" + text1.substring (text1.indexof ("boundary =") + 9). tochararray ());
Int num2 = convert. toint32 (request1.getknownrequestheader (11 ));
Progress progress1 = new progress ();

Application1.context. Items. Add ("filelist", new hashtable ());

Byte [] buffer2 = request1.getpreloadedentitybody ();
Num1 + = buffer2.length;

String text2 = This. analysepreloadedentitybody (buffer2, "uploadguid ");
If (text2! = String. Empty)
{
Application1.context. Items. Add ("lionsky_uploadmodule_uploadguid", text2 );
}
Bool flag1 = true;
If (num2> This. uploadfilelength () & (0> span1.totalhours) | (span1.totalhours> 3 )))
{
Flag1 = false;
}
If (0> span1.totalhours) | (span1.totalhours> 3 ))
{
Flag1 = false;
}
String text3 = This. analysepreloadedentitybody (buffer2, "uploadfolder ");
Arraylist list1 = new arraylist ();
Requeststream stream1 = new requeststream (buffer2, buffer1, null, requeststream. filestatus. Close, requeststream. readstatus. noread, text3, flag1, application1.context, String. Empty );
List1.addrange (stream1.readbody );
If (text2! = String. Empty)
{
Progress1.filelength = num2;
Progress1.ededlength = num1;
Progress1.filename = stream1.originalfilename;
Progress1.filecount = (hashtable) application1.context. items ["filelist"]). count;
Application1.application ["_ uploadguid _" + text2] = progress1;
}
If (! Request1.isentireentitybodyispreloaded ())
{
Byte [] buffer4;
Arraylist list2;
Int Number3 = 204800;
Byte [] buffer3 = new byte [num3];
While (num2-num1)> = num3)
{
If (! Application1.context. response. isclientconnected)
{
This. clearapplication (application1 );
}
Num3 = request1.readentitybody (buffer3, buffer3.length );
Num1 + = num3;
List2 = stream1.contentbody;
If (list2.count> 0)
{
Buffer4 = new byte [list2.count + buffer3.length];
List2.copyto (buffer4, 0 );
Buffer3.copyto (buffer4, list2.count );
Stream1 = new requeststream (buffer4, buffer1, stream1.filestream, stream1.fstatus, stream1.rstatus, text3, flag1, application1.context, stream1.originalfilename );
}
Else
{
Stream1 = new requeststream (buffer3, buffer1, stream1.filestream, stream1.fstatus, stream1.rstatus, text3, flag1, application1.context, stream1.originalfilename );
}
List1.addrange (stream1.readbody );
If (text2! = String. Empty)
{
Progress1.ededlength = num1;
Progress1.filename = stream1.originalfilename;
Progress1.filecount = (hashtable) application1.context. items ["filelist"]). count;
Application1.application ["_ uploadguid _" + text2] = progress1;
}
}
Buffer3 = new byte [num2-num1];
If (! Application1.context. response. isclientconnected & (stream1.fstatus = requeststream. filestatus. Open ))
{
This. clearapplication (application1 );
}
Num3 = request1.readentitybody (buffer3, buffer3.length );
List2 = stream1.contentbody;
If (list2.count> 0)
{
Buffer4 = new byte [list2.count + buffer3.length];
List2.copyto (buffer4, 0 );
Buffer3.copyto (buffer4, list2.count );
Stream1 = new requeststream (buffer4, buffer1, stream1.filestream, stream1.fstatus, stream1.rstatus, text3, flag1, application1.context, stream1.originalfilename );
}
Else
{
Stream1 = new requeststream (buffer3, buffer1, stream1.filestream, stream1.fstatus, stream1.rstatus, text3, flag1, application1.context, stream1.originalfilename );
}
List1.addrange (stream1.readbody );
If (text2! = String. Empty)
{
Progress1.receivedlength = num1 + buffer3.length;
Progress1.filename = stream1.originalfilename;
Progress1.filecount = (hashtable) application1.context. items ["filelist"]). count;
If (flag1)
{
Progress1.uploadstatus = progress. uploadstatusenum. Uploaded;
}
Else
{
Application1.application. Remove ("_ uploadguid _" + text2 );
}
}
}
Byte [] buffer5 = new byte [list1.count];
List1.copyto (buffer5 );
This. populaterequestdata (request1, buffer5 );
}
Catch (exception exception1)
{
This. clearapplication (application1 );
Throw exception1;
}
}
}